/Engine/Source/Editor/MovieSceneTools/Public/KeyframeTrackEditor.h
Returns whether a key was created
virtual bool Apply &40; UMovieSceneSection &42; Section, FMovieSceneChannelProxy & Proxy, FFrameNumber InTime, EMovieSceneKeyInterpolation InterpolationMode, bool bKeyEvenIfUnchanged, bool bKeyEvenIfEmpty &41; const